Stators and rotors composed of a plurality of plate segments receiving coil arrays are known in the state of the art. For simplicity, only stators are considered below, though the designs of course apply as well to rotors.
Conventionally stators are made of a plurality of partly annular plate segments. These partly annular plate segments are stamped out of sheetmetal and then combined and stacked into rings. The plate segments are offset from one another to stabilize the generally unstable stacked plate segments. The individual plate segments are fitted with passage apertures which during assembly are slipped onto positioning pins to attain predetermined positioning and orientation of the plate segments.
Once the ring composed of plate segments has been put together, protrusions constituted at the inner periphery of the plate segments will receive coil arrays which are wound manually or using special winding apparatus. Then a hollow-cylindrical respectively annular housing is slipped over the outer periphery of the plate elements. Lastly the entire assembly as a rule is cast (potted) in a plastic in order to attain final dimensional stability required in the subsequent application. To cast said assembly, it is slipped onto a mandrel which centers it and also serves as an inner casting form. The housing serves as the outer form.
This manufacturing procedure incurs the substantial drawback that given a torque to be generated by the final electrodynamic motor, limits are placed on minimizing the stator size. This drawback is also incurred regarding increasing the torque when the stator size is kept constant. This difficulty arises in part because enough space must be allowed in the stator's inside space defined by the assembled plate segments for winding the coil arrays. Moreover, because of said winding, when the plate segment ring already has been assembled, only a low packing factor is attained as a result of said winding, said factor being typically between 35 and 40%. Obviously pre-wound coil arrays might also be used, which subsequently shall be inserted into the inner space defined by the installed plate segments. This procedure however negatively affects the stator design size because the subsequent stator insertion shall require more space for winding.
Another problem arising in the above manufacture of stators is that gaps are subtended, during plastic casting, between the outer periphery of the annularly stacked plate segments and the inside diameter of a housing slipped over said segments—if there is such a housing, where said gaps fill with plastic during its casting. As a result direct contact is lacking at many sites between the plate segments and the housing, the heat transfer from the plate segments to the stator being commensurately degraded. Therefore subsequent operation of the stator may entail overheating the electrical machine due to inadequate heat dissipation.
In the light of the above state of the art, one objective of the present invention is to create a stator or rotor of an electrodynamic machine or the like based on a different design, further an alternative method to manufacture such a stator or rotor, also an electrodynamic machine fitted with such a stator or rotor, where said drawbacks at least shall be mitigated.